Optical recording medium and recording apparatus

ABSTRACT

An optical recording medium having a track on which data has been previously recorded, comprising on the track a plurality of data block regions each of which includes main data of a block which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data, and linking regions each of which has pseudo data and is inserted between the data block regions. When the linking regions on said track are adjacent, recording patterns of the pseudo data of the adjacent linking regions are different from each other. Further provided is a recording apparatus forming the data block regions and linking regions on a recording medium.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an optical recording medium andto a recording apparatus for forming the recording medium.

[0003] 2. Description of the Related Art

[0004] On a recordable optical recording medium such as DVD-R andDVD-RW, when new information data is written behind a location that hasalready been written, a linking region is formed at that junctionportion. Synchronization data for reading the information data writteninto a data region, which follows the linking region, is written intothe linking region.

[0005] However, the fact that linking regions are formed on such arecordable recording medium leads to a problem that there is apossibility of incompatibility in the recording format with read-onlyrecording media such as DVD-ROMs that are not recordable.

SUMMARY OF THE INVENTION

[0006] It is an object of the present invention to provide a read-onlyoptical recording medium that is compatible with recordable opticalrecording media in the recording format and, apparatus and method forforming the read-only optical recording medium.

[0007] An optical recording medium having recorded data on a trackthereof, according to the present invention, comprises on the track: aplurality of data block regions each of which includes main data of ablock which serves as an error correction unit for the main data andwhich is divided into a predetermined number of main data pieces, eachof which has data for identifying the main data; and linking regionseach of which has pseudo data and is inserted between the plurality ofdata block regions; wherein when the linking regions on the track areadjacent, recording patterns of the pseudo data of the adjacent linkingregions are different from each other.

[0008] A recording apparatus for recording data onto a track of anoptical recording medium, according to the present invention, comprises:a main data recording device which forms on the track a plurality ofdata block regions each of which includes main data of a block whichserves as an error correction unit for the main data and which isdivided into a predetermined number of main data pieces, each of whichhas data for identifying the main data; and a linking data recordingdevice which inserts linking regions each of which has pseudo databetween the plurality of data block regions onto the track; wherein thelinking data recording means, when the linking regions on the track areadjacent, forms the pseudo data of the adjacent linking regions withrecording patterns which are different from each other.

[0009] A recording method for recording data onto a track of an opticalrecording medium, according to the present invention, comprises thesteps of: forming on the track a plurality of data block regions each ofwhich includes main data of a block which serves as an error correctionunit for the main data and which is divided into a predetermined numberof main data pieces, each of which has data for identifying the maindata; and inserting linking regions each of which has pseudo databetween the plurality of data block regions onto the track; wherein whenthe linking regions on the track are adjacent, the pseudo data of theadjacent linking regions is formed with recording patterns which aredifferent from each other.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a block diagram showing the configuration of a recordingapparatus according to the present invention.

[0011]FIG. 2 is a block diagram illustrating the configuration of arandom value generator in the apparatus in FIG. 1.

[0012]FIG. 3 is a diagram showing the data structure of one ECC block.

[0013]FIG. 4 is a diagram showing the data structure of the recordingsignal for one sector.

[0014]FIG. 5 is a diagram showing a linking region between ECC blocks.

[0015]FIG. 6 is a diagram showing the position of each linking region ona track.

[0016]FIG. 7 is a diagram showing linking regions closely positionedbetween adjacent track portions.

[0017]FIG. 8 is a diagram showing a linking region including addressdata that is arranged between ECC blocks.

[0018]FIG. 9 is a block diagram of the configuration of a recordingapparatus as another embodiment of the present invention.

[0019]FIG. 10 is a block diagram of the configuration of a recordingapparatus as another embodiment of the present invention.

[0020]FIG. 11 is a block diagram of the configuration of a recordingapparatus as another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be described below in more detail withreference to the accompanying drawings in accordance with theembodiments.

[0022]FIG. 1 shows an original disk recording apparatus according to thepresent invention. The recording apparatus records information onto anoriginal recording disk 1 for DVD-ROMs, and includes a master clockgenerator 11, a PLL circuit 12, a recording signal generation circuit13, an optical modulator 14, a recording actuator 15, a spindle motor16, a servo controller 17, and a main controller 18.

[0023] The master clock generator 11 generates a master clock signal,and supplies the master clock signal to the PLL circuit 12 and the servocontroller 17. The servo controller 17 is supplied with the master clocksignal, and with a frequency signal FG indicating a rotation frequencyfrom the spindle motor 16. The servo controller 17 carries out rotationcontrol for the spindle motor 16 such that the frequency signal FG issynchronized with the master clock signal, that is, it carries outspindle servo control.

[0024] The PLL circuit 12 generates a recording clock signal based onthe master clock signal. The recording signal generation circuit 13includes a data generation portion 20, an ECC block generation circuit21, a random value generator 22, a timing circuit 23, a switchingcircuit 24, a modulator 25, and a synchronization adding circuit 26. Thedata generation portion 20 outputs information data (main data) to berecorded and address data corresponding to the information data. The ECCblock generation circuit 21 outputs sector data adopted to ECC (errorcorrection code) blocks based on the information data and the addressdata. The random value generator 22 generates random data for linkingregions. The timing circuit 23 generates a timing signal for each ECCblock in response to the recording clock signal. The switching circuit24 selectively outputs one of information data in the ECC block and therandom data in accordance with the timing signal. The modulator 25performs 8-16 modulation for data output from the switching circuit 24.The synchronization adding circuit 26 adds a synchronization code havinga 14T synchronization pattern to the modulated data so as to output arecording signal. The main controller 18 controls the components 20 to26 inside the recording signal generation circuit 13 in synchronizationwith the output clock of the PLL circuit 12.

[0025] The optical modulator 14 modulates laser light in accordance withthe recording signal output from the recording signal generation circuit13, and supplies the modulated laser light to a recording actuator 15.The recording actuator 15 irradiates the laser light onto the recordingportion of the original recording disk 1 rotated by the spindle motor16, thus carrying out exposure.

[0026] As shown in FIG. 2, the random value generator 22 includes amemory 31, eleven D flip-flop circuits 32 to 42, and one adder 44. Aninitial value of eleven bits is previously stored in the memory 31, andeach one bit is supplied to the D flip-flops circuits 32 to 42 inresponse to a command from the main controller 18 at the beginning ofrecording of the original recording disk 1. Each of the D flip-flopscircuits 32 to 42 has a preset input, and the bits corresponding to theinitial value is respectively supplied to those preset inputs from thememory 31. In response to the clock, each of the D flip-flops circuits32 to 42 outputs from the output Q one bit of data supplied to the inputD. The D flip-flops circuits 32 to 42 are connected in the form of aring via the adder 44. That is to say, the adder 44 is connected betweenthe flip-flop circuits 32 and 33, and the output Q of the flip-flopcircuit 42 is connected to the adder 44 and to the input D of theflip-flop circuit 32. The adder 44 adds data of the output Q of theflip-flop circuit 32 and data of the output Q of the flip-flop circuit42, and supplies a result of the addition to the input D of theflip-flop circuit 33. Data having eight bits for the linking region isoutput from the outputs Q of the D flip-flop circuits 35 to 42. Thelinking region data is pseudo data of an information data piece.

[0027] The following is an explanation of the operation of the originaldisk recording apparatus according to the present invention.

[0028] Based on information data and address data to be recorded, theECC block generation circuit 21 successively produces and outputs a datapieces of 91 bytes.

[0029] In the DVD format, one ECC block has sixteen sectors, as shown inFIG. 3. Each sector has a data structure of 13 rows×182 bytes. 91 bytesof each row constitute one data piece, so that each row has two datapieces (91 bytes×2).

[0030] The data pieces are supplied via the switching circuit 24 to themodulator 25. After having been subjected to 8-16 modulation, the datapieces are supplied to the synchronization adding circuit 26. Thesynchronization adding circuit 26 adds a synchronization code (32 bits)including a 14T synchronization pattern to the data pieces having 182bytes (1456 bits) that have been modulated, to generate a recordingsignal. The synchronization code is one of eight codes SY0 to SY7, andserves as identification data for identifying data position in eachsector.

[0031]FIG. 4 illustrates the data structure of the recording signal forone sector. The synchronization code (SY0 to SY7) is located before themodulated data pieces, and two pairs of synchronization code and datapiece are arranged in each row.

[0032] On the other hand, at the time of the beginning of the recording,the initial value is output from the memory 31 to the eleven D flip-flopcircuits 32 to 42 in the random value generator 22. Each of the Dflip-flop circuits 32 to 42 outputs a corresponding bit value of theinitial value. The output values of the D flip-flop circuits 35 to 42then serve as the linking region data. After that, whenever a clocksignal is supplied, each of the D flip-flop circuits 32 to 42 read theoutput value of each of the D flip-flop circuits or the adder 44connected to each input side, and the D flip-flop circuits 35 to 42output as eight bits (one byte) of linking region data. As the clock issupplied to the clock terminals C of the D flip-flops 32 to 42 for everylinking region, for example, the linking region data is renewed at eachclock by an adding operation of the adder 44. The linking region data ispseudo data of the above-described data pieces, and consists of 91bytes. For one linking region, linking region data of 91×2 bytes isgenerated.

[0033] The switching circuit 24 performs a switching operation inresponse to the timing signal after relaying the data pieces for one ECCblock portion from the ECC block generation circuit 21. Thus, theswitching circuit 24 becomes a state in which the output data from therandom value generator 22 is relayed to the modulator 25. The linkingregion data is supplied from the random value generator 22 via theswitching circuit 24 to the modulator 25. After being subjected to 8-16modulation, the linking region data is supplied to the synchronizationadding circuit 26. The synchronization adding circuit 26 adds a linkingregion synchronization code (32 bits) including a 14T synchronizationpattern to the linking region data of 182 bytes (1456 bits) that havebeen modulated, to generate a recording signal. The firstsynchronization code of one row is SYX, and the second synchronizationcode is SYY. Each of the synchronization codes SYX and SYY has a patternthat is different from the synchronization codes SY0 to SY7, andrepresents a linking region.

[0034] The linking region is formed between ECC blocks (data blockregions), and as shown in FIG. 5, includes two synchronization framesthat are arranged between one ECC block (n−1) and the next ECC block(n).

[0035] The recording signal output from the recording signal generationcircuit 13 modulates laser light in the optical modulator 14, and afterthe modulation, the laser light is supplied to the recording actuator15. The recording actuator 15 irradiates the laser light onto therecording portion of the original recording disk 1, which is rotated bythe spindle motor 16, and thus exposure is performed.

[0036] After producing a master disk from the original recording disk 1,optical disks are obtained by duplication with a stamper of the masterdisk.

[0037] Linking regions are formed on each track portion of the opticaldisk, as shown in FIG. 6 for example. Furthermore, between any adjacenttrack portions, the linking regions may be formed adjacently to oneanother, as shown in FIG. 7. However, since the random value generatedfrom the random value generator 22 is used for the linking region dataas described above, the data patterns of the linking region of theadjacent track portions are different from one another. For example, inthe data patterns of adjacent linking regions shown in FIG. 7, the firstpattern, the second pattern and the third pattern are mutuallydifferent.

[0038] In order to accurately read the information recorded on theoptical disk, a tracking control for controlling a reading light beam ona recording track is performed. The phase-difference method can be usedas the tracking control for high-density optical disks such as DVD-ROMs.In the phase-difference method, a tracking error signal is generated,which indicates the error between the irradiation position of the lightbeam and the recording track, in accordance with the difference betweenthe sum signals of the light-receiving signals of oppositelight-receiving portions in a photodetector partitioned into fourpartitions. In the case of the phase-difference method, when thecorrelation between adjacent track portions is strong, then the trackingerror signal includes cross-talk components from the adjacent trackportions, so that the tracking control becomes instable. If there areadjacent linking regions in adjacent track portions, the data pattern ofthose linking regions are different from one another, so that thecorrelation of the adjacent track portions can be reduced. Thus, it ispossible to attain a stable tracking control even when using thephase-difference method for the tracking control.

[0039] It is possible that the random value generator 22 uses currentaddress data (which indicates an address of the adjacent data region) asthe initial value. That is to say, as indicated by a dashed line in FIG.1, address data may be supplied to the random value generator 22, andthe address data may be input from the preset input into the D flip-flopcircuits 32 to 42 when the first linking region has been reached, togenerate the linking region data. Furthermore, it is also possible toprepare a plurality of initial values in the memory 31, and to selectone of the plurality of initial values in accordance with the addressdata.

[0040] If the address data is used as the initial value, then theaddress data may also be recorded together with the random linkingregion data in the random value generator 22. For example, as shown inFIG. 8, the synchronization codes SYX and SYY, the address data and thelinking region data are arranged in that order in the twosynchronization frames of the linking region. If the random valuegeneration pattern of the random value generator 22 corresponding to theinitial value is previously known, then it is possible to read out theaddress data and the linking region data, and to use the linking regiondata as useful data, based on the relation between the address data andthe linking region data.

[0041] Moreover, as shown in FIG. 9, it is also possible to connect therandom value generator 22 in series with a random value generator 28having the same configuration as the generator 22.

[0042] Furthermore, as a configuration for generating linking regiondata, it is also possible to use a random value generator 22, ascrambling circuit 29 and a memory 30, as shown in FIG. 10. Thescrambling circuit 29 consists of an EX-OR circuit. Scrambling data ofeight bits is previously written into the memory 30. In the scramblingcircuit 29, the EX-OR value of the scrambling data and the linkingregion data generated by the random value generator 22 for each linkingregion is obtained, and that value is used as the final linking regiondata.

[0043]FIG. 10 shows another configuration example of a recording signalgeneration circuit 13. In the linking region data generation portion inFIG. 10, it is possible to connect the random value generator 22 inseries with a random value generator 28, as in the configuration shownin FIG. 9. Furthermore, it is also possible to supply the address datato the random value generator 22, as indicated by a dashed line in FIG.10, and to use the address data at the time of the beginning ofrecording as the initial value.

[0044]FIG. 11 shows another configuration example of a recording signalgeneration circuit 13. In the recording signal generation circuit 13 inFIG. 11, the ECC block generation circuit 21, the modulator 25, thesynchronization adding circuit 26 and the switching circuit 24 areconnected in that order, and the switching circuit 24 is provided in thestage following the synchronization adding circuit 26. The random valuegenerator 22 and a modulator 22 a are provided as a configuration forgenerating linking region data. After the linking region data outputfrom the random value generator 22 have been subjected to 8-16modulation by the modulator 22 a, the data is supplied to the switchingcircuit 24. In accordance with the timing signal output from the timingcircuit 23, the switching circuit 24 selectively supplies either theoutput data of the synchronization adding circuit 26 or the output dataof the modulator 22 a to the optical modulator 14. Thus, nosynchronization code is added to the linking region data, so that thelinking region formed between the ECC blocks on the track of the disk 1has only linking region data that is pseudo data not including thesynchronization code.

[0045] In the recording apparatus as described above, linking datarecording means forms the pseudo data of the adjacent linking regionswith recording patterns which are different from each other. In theoptical recording medium, the recording patterns of pseudo data oflinking regions that are located on adjacent track portions of a trackare different from one another. Thus, it is possible to provideread-only non-recordable optical recording media such as DVD-ROMs andrecordable optical recording media such as DVD-RWs, with compatibilityregarding the recording format. As a result, recording medium playerscan be designed with a simple configuration. This application is basedon Japanese Patent Applications No. 2002-234476 and No. 2003-019159which are hereby incorporated by reference.

What is claimed is:
 1. An optical recording medium having recorded data on a track thereof, comprising on said track: a plurality of data block regions each of which includes main data of a block which serves as an error correction unit for the main data and which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data; and linking regions each of which has pseudo data and is inserted between said plurality of data block regions; wherein when the linking regions on said track are adjacent, recording patterns of the pseudo data of the adjacent linking regions are different from each other.
 2. An optical recording medium according to claim 1, wherein the pseudo data has the same length as said main data piece, and wherein each of said linking regions includes said pseudo data and data added to the pseudo data, for identifying the linking region.
 3. An optical recording medium according to claim 1, wherein for each of said linking regions, the pseudo data is generated as a random value based on address data of an adjacent data block region and is recorded together with the address data.
 4. A recording apparatus for recording data onto a track of an optical recording medium, comprising: a main data recording device which forms on the track a plurality of data block regions each of which includes main data of a block which serves as an error correction unit for the main data and which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data; and a linking data recording device which inserts linking regions each of which has pseudo data between said plurality of data block regions onto said track; wherein said linking data recording means, when the linking regions on said track are adjacent, forms the pseudo data of the adjacent linking regions with recording patterns which are different from each other.
 5. A recording apparatus according to claim 4, wherein each of said linking regions inserted by said linking data recording device includes the pseudo data which has the same length as said main data piece, and data added to the pseudo data, for identifying the linking region.
 6. A recording apparatus according to claim 4, wherein said linking data recording device includes a random value generator which generates a random value as the pseudo data for each of said linking regions.
 7. A recording apparatus according to claim 4, wherein said linking data recording device includes a first random value generator which generates a random value as an initial value when recording of data is begun on said optical recording medium, and a second random value generator which generates a random value as the pseudo data in accordance with the initial value for each of the linking regions.
 8. A recording apparatus according to claim 4, wherein said linking data recording device includes a random value generator which generates a random value as the pseudo data in accordance with address data of the adjacent data block region for each of the linking regions.
 9. A recording apparatus according to claim 8, wherein said linking data recording device forms said linking regions each including the address data and the pseudo data based on the address data.
 10. A recording apparatus according to claim 4, wherein said linking data recording device includes a random value generator which generates a random value for each of the linking regions, and a scrambling circuit which generates the pseudo data for each of the linking regions in accordance with the random value and predetermined scrambling data.
 11. The recording apparatus according to claim 10, wherein said scrambling circuit is an exclusive OR circuit.
 12. A recording method for recording data onto a track of an optical recording medium, comprising the steps of: forming on the track a plurality of data block regions each of which includes main data of a block which serves as an error correction unit for the main data and which is divided into a predetermined number of main data pieces, each of which has data for identifying the main data; and inserting linking regions each of which has pseudo data between said plurality of data block regions onto said track; wherein when the linking regions on said track are adjacent, the pseudo data of the adjacent linking regions is formed with recording patterns which are different from each other. 